A small 2-kg sphere B is attached to the bar AB of negligible mass which is supported at A by a pin and bracket and connected at C to a moving support D by means of a spring of constant k = 3.6 kN/m. Knowing that support D undergoes a vertical displacement δ = δm sin ωft, where δm = 3 mm and ωf = 15 rad/s, determine (a) the magnitude of the maximum angular velocity of bar AB, (b) the magnitude of the maximum acceleration of sphere B.